1. Field of the Invention
The disclosure relates generally to a semiconductor memory device, and more particularly relates to NAND flash memory devices, and methods for reading data.
2. Description of the Related Art
Recently, application of a flash memory with SPI (Serial peripheral Interface), required 512 Mb, 1 Gb or more highly integrated. At the same time, lower costs are also being required for memory units, such as flash memory NANDs.
Even with the smallest NAND flash memory array size, address transition thereof, is still slower than that of a NOR memory. Therefore, a continuous read operation of a wrap-around causes problems. FIGS. 9a-9d shows a schematic diagram illustrating an embodiment of a reading operation of a conventional flash memory device. In reading the wrap-around operation, for example, as shown in FIG. 9a, the n-th page of memory array MA is selected. The data read from the n-th page is transferred to the page buffer PB and then, as shown in FIG. 9b, the data which is stored in the page buffer PB is transmitted to external sequentially. As shown in FIG. 9c, then the (n+1)-th page selected. The data read from the (n+1)-th page is transferred to the page buffer PB and then, as shown in FIG. 9d, the data stored in the page buffer PB is transmitted to external continually. Thus, before reading the data of the (n+1)-th page, reading of the data of the n-th page must be finished. In other words, when sequentially reading the data of the n-th page is almost finished, then the (n+1)-th page selected. If the (n+1)-th page contains the management data D1 of the data related to the n-th page, the delay time for accessing the management data D1 is long.
The purpose of the invention is to solve the above conventional problems, and to provide a semiconductor memory device with flexible and fast data reading.